System for and method of treating aneurysms

ABSTRACT

An apparatus for treating an aneurysm in a blood vessel includes an occlusion element disposed on a wire, the occlusion element including a cover for covering a neck of an aneurysm and an inner anchoring member. The cover is configured to expand from a compressed configuration in a tube to an expanded configuration when advanced out of a distal end of the tube to cover the neck of the aneurysm. The cover includes a sphere of mesh material formed into a hemisphere including two layers of mesh that is formed by folding a top portion of the sphere into a bottom portion of the sphere. The inner anchoring member is coupled to and extends from the second surface of the cover and is configured to contact an interior surface of the aneurysm. The inner anchoring member may be a cylindrical stem extending from a central portion of the cover.

BACKGROUND

Aneurysms are abnormal bulging or weakening of a blood vessel, often anartery, and can have many complications. A bulging of the blood vesselcan disrupt or put pressure on surrounding tissues. In the brain, thiscan result in a variety of side effects, such as impaired vision,impaired speech, impaired balance, etc. Further, the aneurysm creates avolume that is not along the main flow path of the blood through theblood vessel. It therefore can serve as a location for blood to becomestagnant and, due to swirling eddy currents, can contribute to theformation of a thromboembolism. If the aneurysm ruptures, they can causesevere internal bleeding.

Aneurysms can be treated externally with open surgery. Such procedurestypically involve closing off the entrance or “neck” of the aneurysmwith a device such as vascular clamp or a ligature. However, such opensurgical procedures can be highly invasive and may lead to trauma to theadjacent tissue and other side effects.

Aneurysms can also be treated through endovascular procedures. In oneprocedure, detachable lengths of wires (e.g., coils) are inserted intothe interior volume of the aneurysm using a catheter. The coils areintended to fill the volume of the aneurysm to decrease the flow ofblood into the aneurysm, inducing stagnation of flow and stimulateclotting within the aneurysm. In settings of large cerebral aneurysms,filling of the aneurysm with multiple coils can lead to mass effect thatmay induce brain swelling and be an independent cause for new symptoms.In another procedure, for aneurysms with a relatively large neck, theadjunctive use of stents assists with the retention of the coils withinthe aneurysm. This approach has a contraindication to being used whentreating ruptured aneurysm, due to the need for additionalanti-thrombotic medications. In another procedure, the coils are held inthe volume of the aneurysm with a temporary balloon that is inflated inthe blood vessel. The balloon is deflated and removed once the mass ofcoils is secured. In still another procedure, a stent device is placedin the artery to promote flow of blood past the aneurysm. This leads tostagnation of the blood within the aneurysm and thrombosis inside theaneurysm volume. However, a side branch of a main artery in which thestent device is placed may become trapped or “jailed”, which impedesaccess to the side branch. In other instances, the side branch canbecome clotted off, possibly causing a stroke. Additionally, such aprocedure generally requires the use additional anti-thromboticmedications, which limits the use of such devices in the setting oftreatment of ruptured aneurysms. The stent device is generally formedwith a relatively tight weave. While the tight weave increases theeffectiveness of the stent device in diverting the blood flow, it alsoimpedes or prevents access to the volume of the aneurysm or the jailedartery. In the event that the aneurysm fails to clot, the obstruction ofthe aneurysm by the stent device prevents the possibility of placingembolic devices inside the aneurysm. Additional procedures such as theplacement of additional stents or open surgery may then be required totreat the residual.

All procedures that involve packing the volume of the aneurysm sufferfrom several common shortcomings. First, it can take many coils of wireto fill the volume of the aneurysm, which is time consuming andincreases the time it takes to complete the procedure. Further, thecoils may be compacted over time to occupy a smaller percentage of thetotal volume of the aneurysm. A great enough compaction of the coils canbe considered a recurrence of the aneurysm and may require furthertreatment.

It would be advantageous to provide an improved system and method oftreating an aneurysm.

SUMMARY

One embodiment relates to an apparatus for treating an aneurysm in ablood vessel includes an occlusion element disposed on a wire, theocclusion element including a cover for covering a neck of an aneurysmand an inner anchoring member. The cover is configured to expand from acompressed configuration in a tube to an expanded configuration whenadvanced out of a distal end of the tube to cover the neck of theaneurysm. The cover includes a sphere of mesh material formed into ahemisphere including two layers of mesh that is formed by folding a topportion of the sphere into a bottom portion of the sphere. The inneranchoring member is coupled to and extends from the second surface ofthe cover and is configured to contact an interior surface of theaneurysm. The inner anchoring member may be a cylindrical stem extendingfrom a central portion of the cover.

One embodiment relates to an apparatus for treating an aneurysm in ablood vessel including an occlusion element disposed on a wire. Theocclusion element includes a cover for covering a neck of an aneurysm,an inner anchoring member for contacting an interior surface of ananeurysm, and a central stem connecting the cover and the inneranchoring member. The occlusion element is coupled to the wire on anouter surface of the cover. The cover and the inner anchoring member areconfigured to expand from a compressed configuration while disposed in atube to an expanded configuration when advanced out of a distal end ofthe tube to be positioned within the aneurysm. The cover and the inneranchoring member have a substantially similar diameter and wherein thecentral stem has a diameter less than the diameter of the cover and theinner anchoring member.

The invention is capable of other embodiments and of being practiced orbeing carried out in various ways. Alternative exemplary embodimentsrelate to other features and combinations of features as may begenerally recited in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will become apparent from the following description, appendedclaims, and the accompanying exemplary embodiments shown in thedrawings, which are briefly described below.

FIG. 1 is a schematic cross-section side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according to anexemplary embodiment.

FIG. 2 is schematic cross-sectional bottom view of the aneurysmocclusion device of FIG. 1.

FIGS. 3A-3E are schematic side cross-section views of a catheterdeploying the aneurysm occlusion device of FIG. 1, according to anexemplary embodiment.

FIG. 4 is a schematic cross-section side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 5 is a schematic cross-section view of the occlusion device of FIG.4 inside of a catheter, according to an exemplary embodiment.

FIG. 6 is a schematic cross-section side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 7 is a schematic cross-section side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 8 is a schematic cross-section side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 9 is a schematic cross-section side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 10 is a schematic cross-section view of the occlusion device ofFIG. 7 inside of a catheter, according to an exemplary embodiment.

FIG. 11 is a schematic cross-section side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 12 is a schematic cross-sectional bottom view of an aneurysmocclusion device, according to an exemplary embodiment.

FIG. 13 is a schematic cross-sectional bottom view of an aneurysmocclusion device, according to an exemplary embodiment.

FIG. 14 is a schematic cross-sectional bottom view of an aneurysmocclusion device, according to an exemplary embodiment.

FIG. 15 is a schematic cross-sectional side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 16 is a schematic cross-sectional side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 17 is a schematic bottom view of an outer anchoring member for ananeurysm occlusion device, according to an exemplary embodiment.

FIG. 18A is a schematic top view of a cover for an aneurysm occlusiondevice, according to an exemplary embodiment.

FIG. 18B is a schematic side view of the cover of FIG. 18A in apartially folded configuration.

FIG. 19 is a schematic side view of an endovascular device configured toocclude an aneurysm, according to another exemplary embodiment.

FIG. 20 is a schematic cross-sectional side view of an aneurysm with anendovascular device configured to occlude the aneurysm, according toanother exemplary embodiment.

FIG. 21 is a schematic side view of an aneurysm with an endovasculardevice configured to occlude the aneurysm, according to anotherexemplary embodiment.

FIG. 22 is a schematic side view of an aneurysm with an endovasculardevice configured to occlude the aneurysm, according to anotherexemplary embodiment.

FIG. 23A is a schematic bottom view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 23B is a schematic bottom view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 24 is a schematic side view of an aneurysm with an endovasculardevice configured to occlude the aneurysm, according to anotherexemplary embodiment.

FIG. 25 is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 26A is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 26B is a schematic top view of the aneurysm occlusion device ofFIG. 26A, according to an exemplary embodiment.

FIG. 27 is a schematic side view of an aneurysm with an endovasculardevice configured to occlude the aneurysm, according to anotherexemplary embodiment.

FIG. 28 is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 29 is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 30 is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 31 is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 32A is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 32B is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 32C is a schematic side view of an aneurysm occlusion device,according to an exemplary embodiment.

FIG. 33 is a side view of a mesh sphere, according to an exemplaryembodiment.

DETAILED DESCRIPTION

Referring in general to FIGS. 1-14, an aneurysm occlusion deviceconfigured to treat an aneurysm 10 is shown according to severalexemplary embodiments. The aneurysm 10 is an outwardly extending bulgein the wall 13 of a blood vessel 12 and has an internal volume 14 thatis in fluid communication with the blood vessel 12 through an opening ata neck portion 16. The aneurysm 10 may occur at a portion of the bloodvessel 12 at which the wall 13 is weakened by disease or trauma. In oneembodiment, the aneurysm 10 may be along an artery, such as a cranialartery (e.g., e.g., basilar artery, middle cerebral artery, etc.). Theaneurysm 10, as depicted in the figures is exemplary only and it shouldbe appreciated that the occlusion devices as described herein may beutilized in the treatment of aneurysms of various sizes and locations.For example, the aneurysm 10 may be located between two branches of ablood vessel.

Referring to FIGS. 1-3E, an occlusion device 20 is shown according toone exemplary embodiment disposed in the neck portion 16 of the aneurysm10 to disrupt or halt the flow of blood flow between the vessel 12 andthe internal volume 14 of the aneurysm, thereby reducing the likelihoodthat the aneurysm 10 will rupture. The occlusion device 20 is configuredto be low profile device, minimizing disruptions to surrounding bodies,such as a side branch 18 of the blood vessel 12. The occlusion device 20may be configured to be biodegradable or bioabsorbable material and maybe configured to promote endothelialization.

The occlusion device 20 includes an inner cover 22 (e.g., plate,membrane, etc.) configured to be disposed within the internal volume 14of the aneurysm 10. The inner cover 22 has an outer diameter that isgreater than the diameter of the neck portion 16 when it is fullyexpanded. The inner cover 22 is a thin, flexible, concave body that canbe distorted (e.g., collapsed) to be inserted through the neck portion16 into the internal volume 14 of the aneurysm 10 (e.g., inserted by acatheter) and opened to at least partially occlude the neck portion 16.Concave, as used herein, is meant to describe any body that is contouredto have a hollow or cavity along one side. As shown in FIG. 1, in oneexemplary embodiment, the inner cover 22 may be generally dome-shaped.In another embodiment, the inner cover 22 may have another concave shape(e.g., conical) that is disposed in the neck portion 16 and opens intothe internal volume 14. In one embodiment, cover 22 can be disk shaped.

The inner cover 22 is formed from a flexible (e.g., soft) biocompatiblematerial that can be collapsed into a microcatheter for endovasculardelivery to the aneurysm 10. The flexibility of the inner cover 22allows it to conform to the shape of the interior surface 15 of theaneurysm 10 and more effectively impeded the flow of blood between theaneurysm 10 and the blood vessel 12. Closely conforming to the shape ofthe interior surface 15 of the aneurysm 10 also facilitates the adhesionof the inner cover 22 to the tissue of the aneurysm 10 and the formationof new tissue to close off the neck portion 16.

The inner cover 22 may be sized to fit a specific aneurysm 10. As shownin FIGS. 1-2, the inner cover 22 has a diameter that is greater than thediameter of the neck portion 16 such that a peripheral portion 24 of theinner cover 22 contacts the interior surface 15 of the aneurysm 10. Theflexibility of the inner cover 22 allows the inner cover 22 to beoversized relative to the size of the neck portion 16 without damaging(e.g., rupturing) the aneurysm 10. For example, an inner cover having adiameter of approximately 5 mm may be utilized to occlude an aneurysmhaving a neck portion with a diameter of up to 4 mm; an inner coverhaving a diameter of approximately 8 mm may be utilized to occlude ananeurysm having a neck portion with a diameter of 4-6 mm; and an innercover having a diameter of approximately 12 mm may be utilized toocclude an aneurysm having a neck portion with a diameter of 6-10 mm.

In one embodiment, the inner cover 22 may be formed from a biocompatiblemetal or metal alloy, such as platinum, stainless steel, titanium, atitanium-nickel alloy (e.g., nitinol). For example, the inner cover 22may be a concave disk formed from sheet-cut nitinol. The nitinol alloymay be configured to undergo a secondary heat setting to form thedesired concave shape. According to an exemplary embodiment, the innercover 22 may have a thickness of less than 100 microns, to achieve adesired flexibility. In another embodiment, the inner cover 22 may beformed as a relatively dense mesh such as 37 micron mesh formed by aplurality of wires or fibers that are coupled together (e.g., welded,soldered, woven, etc.).

In another embodiment, the inner cover 22 may be formed from abiocompatible polymer, such as polytetrafluoroethylene (PTFE), modifiedpolyurethane, silicone or other suitable polymer. In still otherexemplary embodiments, the inner cover 22 may be formed from a metal oralloy that is coated with a polymer (e.g., parylene, PTFE, PFE, etc.) toincrease lubricity and biocompatibility and to reduce thrombogenicity.The inner cover 22 may be formed as a solid sheet or membrane or may bea relatively dense mesh. In some embodiments, the inner cover 22 mayinclude laser drilled nylon sheeting to provide a matrix forendothelialization, while reducing the bulk of the segment. Anotherembodiment may involve two photon polymerization, or 3-D printing of abiocompatible material to form the inner cover 22 directly onto thedelivery system, or to overlie a skeleton frame which is attached to thedelivery system, allowing customization of the final shape of the innercover 22 at the time of treatment.

Referring now to FIGS. 3A-3D, the inner cover 22 is shown being deployedby way of a catheter 30 according to an exemplary embodiment. Referringto FIG. 3A, the catheter 30, including a push wire 32, is advancedthrough the blood vessel 12 to the location of the aneurysm 10. A distalend 34 of the catheter 30 is advanced through the neck portion 16 andinto the internal volume 14 of the aneurysm 10 or to a portion of theblood vessel 12 proximate the neck portion 16. The push wire 32 ispositioned within a lumen formed in the catheter 30. The catheter 30 mayhave a single lumen or the push wire 32 may be positioned within one ofseveral lumens formed within the catheter 30. The inner cover 22 iscoupled to a distal end 36 of the push wire 32 and is housed, in acollapsed configuration, within the lumen. In the collapsedconfiguration, the peripheral portion 24 of the inner cover 22 isupstream (e.g., closer to the distal end 34) compared to a centralportion 26 to which the push wire 36 is coupled. Referring to FIG. 3B,the push wire 32 is moved within the lumen relative to the catheter 30until the inner cover 22 begins to emerge from the end 34 of thecatheter 30. The inner cover 22 is configured to expand (e.g., due tothe internal spring forces of the inner cover 22) into an expandedconfiguration within the internal volume 14 as it clears the end 34 ofthe catheter 30. The push wire 32 may be moved relative to the catheter30 by holding the catheter 30 stationary while the push wire 32 isadvanced (e.g., pushing), by holding the push wire 32 stationary andretracting the catheter 30 (e.g., unsheathing), or by a combination ofmovements of the catheter 30 and the push wire 32. The inner cover 22may be partially deployed with the distal end 34 of the catheter 30positioned within the blood vessel 12 or within the aneurysm 10.

Referring to FIG. 3C, the distal end 34 of the catheter 30 is advancedinto the internal volume 14 of the aneurysm 10 before the inner cover 22is fully deployed from the catheter 30. Referring to FIG. 3D, with theinner cover 22 deployed from the catheter 30, the catheter 30 and/or thepush wire 32 is retracted until the inner cover 22 is seated against theinterior surface 15 of the aneurysm. Referring to FIG. 3E, the distalend 36 of the push wire 32 is detached from the inner cover 22 such thatthe catheter 30 and the push wire 32 may be withdrawn from the bloodvessel 12 while the inner cover 22 remains in the neck portion 16 orlower portion of the aneurysm 10. The push wire 32 may be detached fromthe inner cover 22 by any suitable electrical or mechanical cuttingdevice. Alternatively, the inner cover 22 can be removed by retractingthe wire 32, causing cover 22 to engage distal end of tube 30 and beslid off wire 32.

In one embodiment, the inner cover 22 can be formed to be biased towardthe open, expanded position. In another embodiment, the inner cover 22can include a mesh supported by rib members or splines radiatingoutwardly form a center of inner cover 22. The rib members or splinesmay be biased toward an open position in one embodiment. In oneembodiment, the rib members and splines operate in an upside downumbrella operation fashion and lock in the fully open position once thefully open position is reached.

Referring now to FIG. 4-5, an occlusion device 120 is shown according toan exemplary embodiment disposed in the lower portion of the aneurysm 10to disrupt or halt the flow of blood flow between the vessel 12 and theinternal volume 14 of the aneurysm, thereby reducing the likelihood thatthe aneurysm 10 will rupture. The occlusion device 120 is configured tobe low profile device, minimizing disruptions to surrounding bodies,such as a side branch 18 of the blood vessel 12. The occlusion device120 may be configured to be biodegradable or bioabsorbable material andmay be configured to promote endothelialization.

The occlusion device 120 includes an inner cover 122 (e.g., plate,membrane, etc.) disposed within the internal volume 14 of the aneurysm10 and similar to the inner cover 22 described above. The occlusiondevice 120 further includes an inner anchoring member 140 disposedwithin the aneurysm 10. The inner anchoring member 140 is configured toanchor the inner cover 122 within the aneurysm 10 near the neck portion16. The inner anchoring member 140 provides a relatively rigid body thatsupports the inner cover 122 and reduces the likelihood that the innercover 122 will be displaced from the neck portion 16 by the fluidpressure of the blood in the blood vessel 12.

According to an exemplary embodiment, the inner anchoring member 140includes one or more loops of a coil formed from a suitablebiocompatible metal or alloy (e.g., platinum, stainless steel,nickel-titanium alloy, etc.). The metal coil may be similar to the coilsthat are typically utilized in an endovascular coiling procedure. Theinner anchoring member 140 is coupled to the inner cover 122 andincludes at least one coil that contacts the interior surface 15 of theaneurysm 10. The loops of the inner anchoring member 140 do not fill theentire internal volume 14 or a substantial portion of the internalvolume 14. Instead, the inner anchoring member 140 may include only asmall number of loops. In one exemplary embodiment, the inner anchoringmember 140 may include a single loop of the coil. In another embodiment,the anchoring member 140 includes a large number of loops substantiallyfiling the internal volume 14. The orientation, number, and size of theloops of the inner anchoring member 140 may vary depending on the sizeand shape of the aneurysm 10.

Referring now to FIG. 5, the inner cover 122 and the inner anchoringmember 140 are shown disposed within a catheter 30 according to anexemplary embodiment. The inner cover 122 is coupled to a distal end 36of the push wire 32 and is housed, in a collapsed configuration, withinthe lumen of the catheter 30. In the collapsed configuration, theperipheral portion 124 of the inner cover 122 is upstream (e.g., closerto the distal end 34) compared to a central portion 126 to which thepush wire 36 is coupled on a first surface 144. The inner anchoringmember 140 is coupled to a second surface 146 of the inner cover 122opposite the first surface 142 and is disposed within the lumen of thecatheter 30 upstream of the inner cover 122.

The occlusion device 120 including the inner cover 122 and the inneranchoring member 140 is deployed within the aneurysm 10 similar to theprocess described above with reference to FIGS. 3A-3E. With the distalend 34 of the catheter 30 positioned proximate to the neck portion 16 ofthe aneurysm 10, the push wire 32 is moved within the lumen relative tothe catheter 30. The push wire is moved to cause the anchoring member140 to reach the internal volume 14 and coil within the internal volume14.

In one embodiment, the push wire 32 has a circular solid cross sectionand anchoring member 140 has a coiled cross section (e.g., like atelephone cord) to facilitate coiling in the internal volume 14. In oneembodiment, the push wire 32 and the anchoring member 140 have acircular solid cross section. In one embodiment, the push wire 32 andanchoring member have a coiled solid cross section.

After coiling of the anchoring member 140 is complete, the inneranchoring member 140 is pushed out of the catheter and into the internalvolume 14, where it contacts the interior surface 15 of the aneurysm 10.The push wire 32 is moved further until the inner cover 122 begins toemerge from the end 34 of the catheter 30 to expand into the expandedconfiguration within the internal volume 14. The catheter 30 and/or thepush wire 32 is then retracted until the inner cover 122 is seatedagainst the interior surface 15 of the aneurysm 10 and held in place bythe inner anchoring member 140. The distal end 36 of the push wire 32 isdetached from the first surface 146 of the inner cover 122 such that thecatheter 30 and the push wire 32 may be withdrawn from the blood vessel12 while the inner cover 122 remains in the neck portion 16 or the lowerportion of the aneurysm 10 with the inner anchoring member 140 coupledto the second surface 146.

Referring to FIG. 6, in one exemplary embodiment, the anchoring member140 may have a variable stiffness. For example, the inner anchoringmember 140 may be relatively pliable at a proximal end 146 andrelatively stiff at a distal end 148. The relatively stiff distal end148 may be configured to provide additional support to strengthen thewalls of the aneurysm 10. The stiffer portions of the inner anchoringmember 140 may be utilized as framing members to create a structure inthe internal volume 14 of the aneurysm while the more pliant portionsare utilized to fill in the internal volume of the aneurysm and supportthe inner cover 122. The stiffness of the inner anchoring member 140 maybe controlled in a variety of ways, such as by varying the thickness ofthe coil, the radius of the coil, and/or by varying the material used toform the coil.

The more pliant portions of the inner anchoring member may include aremovable sheath or layer to facilitate the positioning of the stifferportions of the inner portions of the anchoring member 140 within theaneurysm 10. The sheath may be removed once the distal end 148 and thestiffer portions of the inner anchoring member 140 are positioned.

In one embodiment, the stiffness of the inner anchoring member 140 maytransition smoothly or incrementally along the length of the inneranchoring member 140 between the distal end 148 and the proximal end146. In other exemplary embodiments, the inner anchoring member 140 mayinclude two or more distinct zones or portions, each with a differentstiffness or other characteristic. The inner anchoring member 140 mayinclude markers or other indicators to delineate the transition from onezone to another. In one embodiment, the indicators may be external, suchas indicators provided on an outer shaft coupled to the push wire, eachof the outer indicators corresponding to the transition from a zone witha first stiffness to a zone with a second stiffness. In anotherembodiment, the indicators may be internal, such as radiopaqueindicators (e.g., a platinum coating) on the inner anchoring member 140between the zones.

In one embodiment, the anchoring member 140 with a variable stiffnesscan be utilized without the inner cover 122. In such an embodiment, theanchoring member 140 fills the internal volume 14. In one embodiment, anumber of anchoring members 140 can be utilized. In one embodiment, thefirst employed anchoring member 140 has a varying stiffness (e.g.,thickness) that is greater than the varying stiffness (e.g., thickness)of the next employed anchoring member.

Referring now to FIG. 7-10, an occlusion device 220 is shown accordingto an exemplary embodiment disposed in the lower portion of the aneurysm20 near or at the neck portion 26 to disrupt or halt the flow of bloodflow between the vessel 22 and the internal volume 14 of the aneurysm20, thereby reducing the likelihood that the aneurysm 20 will rupture.The occlusion device 220 is configured to be low profile device,minimizing disruptions to surrounding bodies, such as a side branch 28of the blood vessel 22. The occlusion device 220 may be configured to bebiodegradable or bioabsorbable material and may be configured to promoteendothelialization.

The occlusion device 220 includes an inner cover 222 (e.g., plate,membrane, etc.) disposed within the internal volume 14 of the aneurysm10 and similar to the inner cover 22, 122 described above. Occlusiondevice 220 also includes an inner anchoring member 240 disposed withinthe aneurysm 10 and similar to the inner anchoring member 140 describedabove. The inner anchoring member 240 is configured to anchor the innercover 222 within the aneurysm 20 near or at the neck portion 16. Theocclusion device 220 further includes an outer anchoring member 250disposed within the blood vessel 12 proximate the aneurysm 10. The outeranchoring member 250 provides a relatively rigid body that supports theinner cover 222 and reduces the likelihood that the inner cover 222 willbe displaced from the neck portion 16 by the fluid pressure of the bloodin the blood vessel 12.

Referring to FIG. 7, according to an exemplary embodiment, the outeranchoring member 250 includes a loop 252 of a coil formed from asuitable biocompatible metal or alloy (e.g., platinum, stainless steel,nickel-titanium alloy, etc.). The metal coil may be similar to the coilsthat are typically utilized in an endovascular coiling procedure. Theloops 252 is coupled to the inner cover 222 and contacts the wall 13 ofthe blood vessel 12 in one embodiment. The loop 252 is orientedperpendicular to the flow of blood through the blood vessel 12 in oneembodiment. Multiple coils or loops 252 can be utilized in oneembodiment.

Referring to FIG. 8, according to an exemplary embodiment, the outeranchoring member 250 includes a first loop 254 and a second loop 256.The loops 254 and 256 may be loops of a coil formed from a suitablebiocompatible metal or alloy (e.g., platinum, stainless steel,nickel-titanium alloy, etc.). At least one of the loops 254 and 256 arecoupled to the inner cover 222 and contact the wall 13 of the bloodvessel 12. The first loop 254 extends about the inner circumference ofthe blood vessel 12 such that it is oriented perpendicular to the flowof blood through the blood vessel 12. The second loop 256 is orientedparallel to the flow of blood through the blood vessel 12. The secondloop 256 is formed of a coil having a fairly small diameter and does notsubstantially impede the flow of blood through the blood vessel. Inother embodiment, the outer anchoring member 250 may include more thantwo loops. The orientation, number, and size of the loops may varydepending on the size and shape of the blood vessel 12.

Referring to FIG. 9, according to another exemplary embodiment, theouter anchoring member 250 includes a stent 258 formed from a suitablebiocompatible metal or alloy (e.g., platinum, stainless steel,nickel-titanium alloy, etc.) or a suitable biocompatible polymer. Thestent 258 is introduced in a collapsed state to the blood vessel 12proximate the aneurysm 10 via the catheter 30. Once deployed into theblood vessel 12, the stent 258 is expanded to engage against the wallsof the blood vessel 12. The stent 258 may be self-expandable or may beexpanded with another device, such as an inflatable balloon. All or partof the stent 258 may be coated or covered with a radiopaque material,such as a platinum to allow for visualization of the stent 258 (e.g.,during and after the placement of the stent 258).

The stent 258 is not intended to occlude the neck portion 16 of theaneurysm 10, but instead forms a structure to facilitate the placementand anchoring of the inner cover 222. The stent 258 therefore does notneed to be as wide as or wider than the neck portion 16, but may be arelatively short body (e.g., shorter than the width of the neck portion16 of the aneurysm 10). The relatively short length of the stent 258reduces the likelihood that the outer anchoring member 250 will disruptsurrounding bodies, such as a side branch 18 of the blood vessel 12.Further, the stent 258 may have a non-dense, relatively openconfiguration with variable cell morphology which may extend proximallyin the blood vessel 12 from the neck portion 16. In other embodiments,the stent 258 may be a solid member, such as a band formed of a metal oralloy with a relatively thin thickness.

In another embodiment, the outer anchoring member 250 may be a temporarymember that is removed with the catheter 30 after the occlusion device320 has been placed in the neck portion 16 of the aneurysm and has beencoupled to the walls of the aneurysm 10. For example, the outeranchoring member may be a balloon that is inflated in the blood vessel12 proximate the aneurysm to provide a temporary structure to supportthe inner cover 222.

Referring now to FIG. 10, the inner cover 222, the inner anchoringmember 240, and the outer anchoring member 250 are shown disposed withina catheter 30 according to an exemplary embodiment. The outer anchoringmember 250 is coupled to a distal end 36 of the push wire 32 and ishoused, in a collapsed configuration, within the lumen of the catheter30. The outer anchoring member 250 is coupled to the inner cover 222,which is housed, in a collapsed configuration, within the lumen of thecatheter 30 upstream of the outer anchoring member 250. The outeranchoring member 250 may be coupled to the inner cover 222, for example,with an adhesive. In the collapsed configuration, a peripheral portion224 of the inner cover 222 is upstream of a central portion 226 to whichthe outer anchoring member 250 is coupled on a first surface 244. Theinner anchoring member 240 is coupled to a second surface 246 of theinner cover 222 opposite the first surface 242 and is disposed withinthe lumen of the catheter 30 upstream of the inner cover 222.

The occlusion device 220 including the inner cover 222 and the inneranchoring member 240 is deployed within the aneurysm 20 similar to theprocess described above with reference to FIGS. 3A-3E. With the distalend 34 of the catheter 30 positioned proximate to the neck portion 16 ofthe aneurysm 10, the push wire 32 is moved within the lumen relative tothe catheter 30. The inner anchoring member 240 is pushed out of thecatheter and into the internal volume 14, where is contacts the interiorsurface 25 of the aneurysm 20. The push wire 32 is moved further untilthe inner cover 222 begins to emerge from the end 34 of the catheter 30to expand into an expanded configuration within the internal volume 14.The catheter 30 and/or the push wire 32 is then retracted until theinner cover 222 is seated against the interior surface 25 of theaneurysm 20 and held in place by the inner anchoring member 240. Thepush wire 32 is moved further until the outer anchoring member 250emerges from the catheter 30. The outer anchoring member 250 may be, forexample, one or more loops 252, 254, or 256, or the stent 258. Thedistal end 36 of the push wire 32 is detached from the outer anchoringmember such that the catheter 30 and the push wire 32 may be withdrawnfrom the blood vessel 22 while the inner cover 22 remains near or in theneck portion 16 of the aneurysm 20 with the inner anchoring member 240coupled to the second surface 246 and the outer anchoring member 250disposed in the blood vessel 12. In other embodiments, the push wire 32may be coupled directly to the inner cover 222 and the outer anchoringmember 250 may be deployed separately (e.g., from another catheter).

Referring now to FIG. 11-14, an occlusion device 320 is shown accordingto an exemplary embodiment disposed in the neck portion 16 of theaneurysm 10 to disrupt or halt the flow of blood flow between the vessel12 and the internal volume 14 of the aneurysm, thereby reducing thelikelihood that the aneurysm 10 will rupture. The occlusion device 320is configured to be low profile device, minimizing disruptions tosurrounding bodies, such as a side branch 18 of the blood vessel 12. Theocclusion device 320 may be configured to be biodegradable orbioabsorbable material and may be configured to promoteendothelialization.

The occlusion device 320 includes an inner cover 322 (e.g., plate,membrane, etc.) disposed within the internal volume 14 of the aneurysm10 and similar to the inner cover 22, 122, or 222 described above. Theocclusion device 320 further includes an outer cover 360 disposed in theblood vessel 12 proximate the aneurysm 10. The outer cover 360 may becoupled to the inner cover 322 provides a relatively rigid body tosupport the inner cover. The outer cover 360 reduces the likelihood thatthe inner cover 322 will be displaced from the neck portion 16 by thefluid pressure of the blood in the blood vessel 32. The outer cover 360may be utilized instead of or in addition to other devices, such as theinner anchoring member 140 or the outer anchoring member 250 to securethe inner cover 322 in the neck portion 16.

Referring to FIG. 11, according to an exemplary embodiment, the outercover 360 is a relatively thin member (e.g., plate, sheet, etc.) formedfrom a suitable biocompatible such as a metal or alloy (e.g., platinum,stainless steel, nickel-titanium alloy, etc.), or a polymer (e.g., PTFE,etc.). According to an exemplary embodiment, the outer cover 360 has athickness of less than 2 mm. According to a preferred embodiment, theouter cover has 360 has a thickness of less than 1 mm. The outer cover360 is a low-profile body that does not substantially impede the flow ofblood through the blood vessel 12. The outer cover 360 includes aperipheral portion 362 that contacts the wall 13 of the blood vessel 12around the neck portion 16 of the aneurysm 10 and a central portion 364disposed in the neck portion 16. The central portion 364 may beintegrally formed with the inner cover 322 or may be coupled to theinner cover 322 (e.g., with a suitable adhesive). All or part of theouter cover 360 may be coated or covered with a radiopaque material,such as a platinum, to allow for visualization of the outer cover 360(e.g., during and after the placement of the outer cover 360). Inembodiment, outer cover 360 is attached to inner cover at a center areahaving less area than the neck portion 16 (e.g., 90 percent, 75 percent,or 50 percent of the area of the neck portion). In one embodiment, thecenter area has a circular shape.

The outer cover 360 is not intended to occlude the neck portion 16 ofthe aneurysm 10, but instead forms a structure to facilitate anchor theinner cover 322. The outer cover 360 therefore does not need tocompletely cover the neck portion 16. The outer cover 360 may thereforebe shaped such that portions of the neck portion 16 are uncovered and/ormay be formed of a porous material (e.g., a mesh). Referring to FIG. 12,in one embodiment, the outer cover 360 may be a sheet that completelycovers the neck portion 16 such that the peripheral portion 362 of theouter cover 360 extends about the entirety of the neck portion 16.

Referring to FIG. 13, in another embodiment, the outer cover 360 mayinclude multiple segments or sections such as radial lobes 366 thatextend outward from the neck portion 16. Each of the lobes 366 mayinclude a central portion 364 disposed within the neck portion 16 and aperipheral portion 362 extending beyond the neck portion 16 to contactthe wall 13 of the blood vessel 12.

Referring to FIG. 14, in another embodiment, the outer cover 360 mayinclude a spiral body 368. The inner loops of the spiral body 368 mayform the central portion 364 while the outer loops of the spiral body368 may form the peripheral portion 362.

The outer cover 360 may be deployed from a catheter in the sameprocedure as the inner cover 322. The outer cover 360 may therefore beconfigured to be collapsible such that it can be coupled to the innercover 322 and housed within the catheter. The outer cover 360 may beconfigured such that, within the catheter, the central portion 364 iscoupled to the inner cover 322 and positioned upstream of the peripheralportion 362. The inner cover 322 may be deployed as described withreference to FIGS. 3A-D. Once the inner cover 322 is deployed from thecatheter and positioned in the neck portion 16, the push wire of thecatheter may be advanced further to deploy the outer cover 360. Thefluid pressure of the blood within the blood vessel 12 forces the outercover 360 against the wall 13 of the blood vessel 12. In otherembodiments, the push wire 32 may be coupled directly to the inner cover322 and the outer cover 360 may be deployed separately (e.g., fromanother catheter).

Referring now to FIGS. 15-16, an occlusion device 420 is shown accordingto an exemplary embodiment disposed in a lower portion, such as the neckportion 16, of the aneurysm 10. The occlusion device 420 includes aninner cover 422 (e.g., plate, membrane, etc.) disposed within theinternal volume 14 of the aneurysm 10. The occlusion device 420 furtherincludes an inner anchoring member 440 disposed within the aneurysm 10and/or an outer anchoring member 450. The inner anchoring member 440 isconfigured to anchor the inner cover 422 within the aneurysm 10 in theneck portion 16. According to an exemplary embodiment, the inneranchoring member 440 includes one or more struts or arms formed from asuitable biocompatible metal or alloy (e.g., platinum, stainless steel,nick-titanium alloy, etc.). The inner anchoring member 440 is coupled tothe inner cover 422 and is configured to extend beyond the periphery ofthe inner cover 422 to contact the interior surface 15 of the aneurysm10. The inner anchoring member 440 may therefore be used to facilitatethe positioning of the inner cover 422 in an aneurysm 10 having arelatively wide neck 16. The struts or arms of the inner anchoringmember 440 do not fill the entire internal volume 14 or a substantialportion of the internal volume 14. The “mass effect” of the aneurysm 10is reduced, as the size of the aneurysm 10 is allowed to shrink as thevessel heals, thereby reducing the pressure placed on the surroundingtissue by the aneurysm 10. The orientation, number, and length of thearms of the inner anchoring member 440 may vary depending on the sizeand shape of the aneurysm 10. The arms of the inner anchoring member 440may be configured to collapse together to be delivered via amicrocatheter, similar to the microcatheter 30 described above.

Referring still to FIGS. 15-16, the outer anchoring member 450 includesfirst portion 452 (e.g., distal portion) disposed at the neck 16 andcoupled to the inner cover 422 and a second portion 454 (e.g., proximalportion) disposed in the vessel 12. The outer anchoring member 450 isformed from a suitable biocompatible metal or alloy (e.g., platinum,stainless steel, nickel-titanium alloy, etc.) or a suitablebiocompatible polymer. All or part of the outer anchoring member 450 maybe coated or covered with a radiopaque material, such as a platinum toallow for visualization of the outer anchoring member 450 (e.g., duringand after the placement of the outer anchoring member 450). The outeranchoring member 450 is introduced in a collapsed (e.g., straightened)state to the blood vessel 12 proximate the aneurysm 10 via a catheter.Once deployed into the blood vessel 12, the outer anchoring member 450expands such that at least a portion of the outer anchoring membercompresses against the walls of the blood vessel 12. The outer anchoringmember 450 may be formed as a single, continuous spiral, with loops ofthe spiral being formed to have variable properties (e.g., diameter,thickness, flexibility, etc.). For example, the first portion 452 may beformed to have relatively small diameter, flexible coils while thesecond portion 454 may be formed to have larger, relatively rigid coilsproviding an increased outward radial force to facilitate positioningthe outer anchoring member 450 along the wall 13 of the blood vessel 12.

Referring to FIG. 17, according to another exemplary embodiment, aportion of an outer anchoring member 460 may be formed as a dual spiral.According to other exemplary embodiments, the outer anchoring member maybe formed as a wide variety of other shapes (e.g., web-shaped,star-shaped, etc.) to provide a desired flexibility and support for theinner cover at the neck of the aneurysm.

Referring to FIGS. 18A-18B, according to another exemplary embodiment,an inner cover 470 for an occlusion device may be a star-shaped body.The inner cover 470 may be formed (e.g., creased, scored, molded) tofold and collapse along predefined fold lines.

Referring now to FIG. 19, an occlusion device 480 is shown having anouter anchoring member 482. The outer anchoring member 482 is arecapturable body that may be variously shaped (e.g., straight, spiral,multi-spiraled, coven, etc.). The outer anchoring member 482 is formedas a relatively open structure having a minimal number of segments thatform a framework that is capable of positioning and securing theocclusion device 480 while minimizing contact with the walls of theblood vessel. The open nature of the outer anchoring member 482 has alow risk of jailing a branch blood vessel or otherwise altering the flowof blood through the blood vessel.

Referring to FIG. 20, an inner anchoring member 494 for an occlusiondevice 490 is shown according to another exemplary embodiment. The inneranchoring member 494 includes a central wire 496 coupled to the cover492 and one or more outer wires 498 coupled to the central wire 496. Theouter wires 498 extend outward from the central wire 496 to contact theinterior surface 15 of the aneurysm 10. The inner anchoring member 494is introduced in a collapsed (e.g., straightened) state to the aneurysm10 via the catheter 30. Once deployed into the aneurysm 10, the catheter30 is withdrawn, allowing the outer wires 498 to expand outward suchthat at least a portion of the outer wires 298 contact the inner surface15 to position and anchor the cover 492 in the neck 16.

Referring to FIG. 21, an occlusion device 520 is shown according to anexemplary embodiment. The occlusion device 520 is disposed in or nearthe neck portion 16 of the aneurysm 10 to disrupt or halt the flow ofblood flow between the vessel 12 and the internal volume 14 of theaneurysm 10, thereby reducing the likelihood that the aneurysm 10 willrupture. The occlusion device 520 is configured to be low profiledevice, minimizing disruptions to surrounding bodies, such as a sidebranch of the blood vessel. The occlusion device 520 may be configuredto be biodegradable or bioabsorbable material and may be configured topromote endothelialization.

The occlusion device 520 includes an inner cover 522 disposed within theinternal volume 14 of the aneurysm 10. The inner cover 522 is disposedto cover the neck portion 16 of the aneurysm 10. The inner cover 522 isformed of a relatively dense mesh such as micron mesh formed by aplurality of wires or fibers that are coupled together (e.g., welded,soldered, woven, etc.). In this embodiment, the inner cover 522 is adouble layer of mesh. The double layer of mesh is first formed as a meshsphere. In some embodiments, the mesh sphere is collapsed into themicrocatheter 30 for endovascular delivery to the aneurysm 10. As thecover 522 is released from the microcatheter 30, a push wire 32 holds anupper center portion of the mesh sphere such that the mesh sphere isreleased and expands into a hemispherical shape. Turning to FIG. 33, thedouble layered cover 522 is formed by a mesh sphere 521 wherein a first,upper portion 523 of the sphere 521 is enfolded over onto and into thesecond, lower portion 525 of the sphere 521, thereby forming adouble-layered hemisphere shape. The expanded shape of the sphere isdependent on a distance between the upper center of the sphere and alower center of the sphere, and can therefore be adjusted by moving thewire.

The occlusion device 520 including the inner cover 522 may be deployedwithin the aneurysm 20 similar to the process described above withreference to FIGS. 3A-3E. With the distal end 34 of the catheter 30positioned proximate to the neck portion 16 of the aneurysm 10, the pushwire 32 is moved within the lumen relative to the catheter 30. The innercover 522 begins to emerge from the end 34 of the catheter 30 to expandinto an expanded configuration within the internal volume 14. In oneembodiment, the inner cover 522 emerges in the form of the mesh sphere.The catheter 30 and/or the push wire 32 is then retracted until theinner cover 522 is seated against the interior surface 25 of theaneurysm 10. The double layer of inner cover 522 is formed by enfoldingthe top portion of the sphere over the bottom portion, such as bywithdrawing the push wire 32 until the top portion meets the bottomportion. In other embodiments, the inner cover 522 is deployed from thecatheter 30 already in a double layered configuration and does notemerge initially as a sphere.

Referring now to FIG. 22, occlusion device 520 is shown according toanother exemplary embodiment where occlusion device 520 further includesan outer anchoring mechanism 550. The outer anchoring member 550provides support to the inner cover 522 and reduces the likelihood thatthe inner cover 522 will be displaced from the neck portion 16 by thefluid pressure of the blood in the blood vessel 12. In the embodimentshown, the outer anchoring mechanism 550 is formed by two or moresegments or sections such as radial lobes 566 that extend outward fromthe neck portion 16. Each of the lobes 566 may be formed of a singlewire loop made of nitinol, polymer, or similar material. Alternative toa loop, lobes 566 may be a solid, substantially flat piece of materialextending from the inner cover 522. Each of the lobes 566 may include acentral portion 564 configured to be disposed within the neck portion 16and a peripheral portion 562 configured to extend beyond the neckportion 16 to contact the wall 13 of the blood vessel 12. The wire loopmay be formed having a narrower portion near the central portion 564 anda wider portion near the peripheral portion 562, similar to an oarshape. In some embodiments the narrow portion and the wider portion eachhave a uniform diameter, as depicted in the bottom view of the occlusiondevice 520 shown in FIG. 23A. In other embodiments, the diameter of theloop continuously widens between a central-most portion and aperipheral-most portion, as depicted in the bottom view of the occlusiondevice 520 shown in FIG. 23B. Lobes 566 may take on other shapes andsizes in addition to those shown. The occlusion device 520 may haveanywhere from two to eight lobes 566.

Referring back to FIG. 22, the lobes 566 of occlusion device 520 arecoupled to inner cover 522 at an angle 570. In some embodiments, theangle 570 formed between the side of the inner cover 522 and the planeof the radial lobe is between 15 degrees and 45 degrees. In this way,the lobes 566 act as a clip to engage the wall 13 of the blood vessel 12near the neck portion 16, and maintain the positioning of the occlusiondevice 520 in the lower portion of the aneurysm 12 near the neck portion16.

Referring to FIG. 24, in one exemplary embodiment, an occlusion device620 having an inner anchoring member 640 is shown disposed within theaneurysm 10. The inner anchoring member 640 is configured to anchor theinner cover 622 within the lower portion of aneurysm 10, at or near theneck portion 16. The inner anchoring member 640 provides a relativelyrigid body that supports the inner cover 622 and reduces the likelihoodthat the inner cover 622 will be displaced from the neck portion 16 bythe fluid pressure of the blood in the blood vessel 12. According to anexemplary embodiments, the inner cover 622 is a double-layer, formedsimilarly to the inner cover 522. The inner cover 622 has a peripheralportion to contact the interior surface 15 of the aneurysm 10.

According to an exemplary embodiment, the inner anchoring member 640includes one or more loops of a coil formed from a suitablebiocompatible metal or alloy (e.g., platinum, stainless steel,nickel-titanium alloy, etc.). The metal coil may be spring-like and maybe similar to the coils that are typically utilized in an endovascularcoiling procedure. The inner anchoring member 640 is coupled to theinner cover 622 and includes at least one coil that contacts theinterior surface 15 of the aneurysm 10. In the embodiment shown, theloops of the inner anchoring member 640 do not fill the entire internalvolume 14 or a substantial portion of the internal volume 14. Instead,the inner anchoring member 640 includes only a single set of loopsextending from the cover 622 like a stem. In some embodiments, theanchoring member 640 may be a soft net coil. In other embodiments, theanchoring member 640 may include a large number of loops substantiallyfiling the internal volume 14. The orientation, number, and size of theloops of the inner anchoring member 640 may vary depending on the sizeand shape of the aneurysm 10.

Alternatively, the inner cover 622 and the inner cover 522 can beimplemented with any inner anchoring members as described in thisdisclosure. Furthermore, though not depicted in FIG. 24, occlusiondevice 620 may include any of the outer anchoring members as describedin this disclosure, including but not limited to, outer anchoringmembers 250, 360, 450, 460, 482, and 550.

Referring to FIG. 25, in one exemplary embodiment, an occlusion device720 having an inner anchoring member 740 is shown. The inner anchoringmember 740 is configured to anchor the inner cover 722 within the lowerportion of an aneurysm 10, at or near the neck portion 16. The inneranchoring member 740 provides a relatively rigid body that supports theinner cover 722 and reduces the likelihood that the inner cover 722 willbe displaced from the neck portion 16 by the fluid pressure of the bloodin the blood vessel 12. According to an exemplary embodiment, the innercover 722 is a double-layer, formed similarly to the inner cover 522,622. The inner cover 722 has a peripheral portion to contact theinterior surface 15 of the aneurysm 10.

According to an exemplary embodiment, the inner anchoring member 740 issimilar to inner anchoring member 640 in that it extends from asubstantially central portion of the cover 722 like a stem. In thisembodiment, unlike inner anchoring member 640, inner anchoring member740 is a cylindrical stem made from a sheet of mesh material. Thecylindrical stem may be enclosed at a distal end of the stem thatcontacts the interior surface 15 of the aneurysm 10. The mesh materialmay be wrapped around a set of loops forming a coil or may beself-supporting. The inner anchoring member 740 may include a pluralityof folds 742 forming an accordion-type structure that can be contractedwhen pressed against an interior surface 15 of the aneurysm 10. In someembodiments, the mesh material is a very fine, high density wire mesh.The mesh material may be a combination of nitinol interlaced with ametal and thread. In some embodiments, the top end 744 of the inneranchoring member 740 is covered or closed.

The inner anchoring member 740 of FIG. 25 may be constructed as aunitary structure with the cover 722. For example, the same sheet ofmesh can be used to form the cover 722 with an extending portion formingthe stem of the inner anchoring member 740. In other embodiments, thecover 722 and the inner anchoring member 740 are separate elements thatare coupled, or molded, together.

Though not depicted in FIG. 25, occlusion device 720 may include any ofthe outer anchoring members as described in this disclosure, includingbut not limited to, outer anchoring members 250, 360, 450, 460, 482, and550.

Referring to FIG. 26A-B, in one exemplary embodiment, an inner cover 822for an occlusion device is shown. In this embodiment, the inner cover isa multi-layered inner cover 822. Inner cover 822 includes a plurality ofleaves 824 arranged in an overlapping relationship with each other, andwhich are movable individually. The leaves 824 are arranged around acentral portion of the inner cover 822. In the side view of FIG. 26A,the inner cover 822 is shown in a partially contracted configuration,wherein the leaves are positioned tightly around the central portion. InFIG. 26B, which is a top view showing the inner cover in an expandedconfiguration, such as when the inner cover 822 is deployed near theneck 16 of the aneurysm 10, the leaves 824 are extended or fanned out,such that they extend out away from the central portion of the innercover 822. At least a portion of the leaves 824 of inner cover 822 areconfigured to contact the interior surface 15 of the aneurysm 10 when inthe expanded configuration.

The individual leaves 824 of inner cover 822, according to an exemplaryembodiment, are made of a mesh material, such as a biocompatible metalor metal alloy, such as platinum, stainless steel, titanium, atitanium-nickel alloy (e.g., nitinol). Leaves 824 of the inner cover 822may be formed of a relatively dense mesh such as 37 micron mesh formedby a plurality of wires or fibers that are coupled or molded together.The inner cover 822 may be used in combination with an inner anchoringmember as described elsewhere herein, including but not limited to theinner anchoring members and central stems described below and shown inFIGS. 27-32.

FIGS. 27-32 each depict an occlusion device having a similar overallstructure. For example, each of the embodiments shown therein include aninner cover (922, 1022, 1122, 1222, 1322, 1422, 1522, 1622) and an inneranchoring member (940, 1040, 1140, 1240, 1340, 1440, 1540, 1640),connected by a central stem (930, 1030, 1130, 1230, 1330, 1430, 1530,1630). In these embodiments, the inner cover and inner anchoring memberare discs having a substantially similar diameter. The central stem maybe a cylindrical body having a diameter less than the diameter of theinner cover and inner anchoring member. The inner cover, inner anchoringmember, and central stem are all constructed of a mesh material, similarto the occlusion devices described above. In some embodiments of FIGS.27-32, the inner cover is made of a higher density mesh and the inneranchoring member is made of a lower density mesh.

Various arrangements and combinations are shown and described withreference to FIGS. 27-32. It is contemplated that the present design notbe limited to the embodiments shown, but that the various featuresdescribed in FIGS. 27-32 could be used in other combinations andarrangements with one another. Furthermore, any of the embodiments shownin FIGS. 27-32 may also utilize the multi-layer cover 822 shown in FIGS.26A-26B. The embodiments shown may also incorporate any of the outeranchoring members, including but not limited to, outer anchoring members(250, 360, 450, 460, 482, and 550) described above.

Referring to FIG. 27, in one exemplary embodiment, an occlusion device920 is shown disposed within the aneurysm 10. Occlusion device 920 hasan inner cover 922 and an inner anchoring member 940, connected by acentral stem 930. The central stem 930 may be a cylindrical body. Theinner cover 922 and inner anchoring member 940 are each generallyconcave with concavities facing towards the stem 930 and towards oneanother. The inner cover 922, inner anchoring member 940, and centralstem 930 may be constructed separately and coupled together. In otherembodiments, the three elements are formed of a single sheet and areunitary. In this embodiment, both the inner cover 922 and the inneranchoring mechanism 940 are constructed of a single-layer disc of themesh material.

Referring to FIG. 28, in one exemplary embodiment, an occlusion device1020 is shown. Occlusion device 1020 has an inner cover 1022 and aninner anchoring member 1040, connected by a central stem 1030. The innercover 1022 and inner anchoring member 1040 are each generally concavewith concavities facing towards the stem 1030 and towards one another.The inner cover 1022, inner anchoring member 1040, and central stem 1030may be constructed separately and coupled together. In otherembodiments, the three elements are formed of a single sheet and areunitary. Occlusion device 1020 of FIG. 28 differs from occlusion device920 in that both the inner cover 1022 and the inner anchoring mechanism1040 are constructed of a double-layer of the mesh material, which maybe formed in a similar fashion to inner cover 522, 622, or 722 describedabove.

Referring to FIG. 29, in one exemplary embodiment, an occlusion device1120 is shown. Occlusion device 1120 has an inner cover 1122 and aninner anchoring member 1140, connected by a central stem 1130. The innercover 1122 and inner anchoring member 1140 are each generally concavewith concavities facing towards the stem 1130 and towards one another.The inner cover 1122, inner anchoring member 1140, and central stem 1130may be constructed separately and coupled together. In otherembodiments, the three elements are formed of a single sheet and areunitary. Occlusion device 1120 of FIG. 29 differs from occlusion device920 in that the inner cover 1122 is constructed of a single layer ofmesh material and the inner anchoring mechanism 1140 is constructed of adouble-layer of the mesh material, which may be formed in a similarfashion to inner cover 522, 622, or 722 described above.

Referring to FIG. 30, in one exemplary embodiment, an occlusion device1220 is shown. Occlusion device 1220 has an inner cover 1222 and aninner anchoring member 1240, connected by a central stem 1230. The innercover 1222 and inner anchoring member 1240 are each generally concavewith concavities facing towards the stem 1230 and towards one another.The inner cover 1222, inner anchoring member 1240, and central stem 1230may be constructed separately and coupled together. In otherembodiments, the three elements are formed of a single sheet and areunitary. Occlusion device 1220 of FIG. 30 differs from occlusion device920 in that the inner anchoring mechanism 1240 is constructed of asingle layer of mesh material and the inner cover 1222 is constructed ofa double-layer of the mesh material, which may be formed in a similarfashion to inner cover 522, 622, or 722 described above.

Referring to FIG. 31, in one exemplary embodiment, an occlusion device1320 is shown. Occlusion device 1320 has an inner cover 1322 and aninner anchoring member 1340, connected by a central stem 1330. Occlusiondevice 1320 of FIG. 31 is similar to occlusion device 1220 of FIG. 30 inthat the inner anchoring mechanism 1240 is constructed of a single layerof mesh material and the inner cover 1222 is constructed of adouble-layer of the mesh material, which may be formed in a similarfashion to inner cover 522, 622, or 722 described above, however, inthis embodiment, the inner anchoring mechanism 1340 is single-layer, endportion of the central stem 1330 that is flared out forming anatraumatic end 1332 of the stem 1330. An occlusion device may alsoinclude a flared out inner cover in addition to the flared inneranchoring mechanism 1340 shown as part of occlusion device 1320.

FIGS. 32A-32C depict other modifications to the occlusion devices,according to exemplary embodiments. Each of these figures depict anocclusion device having an inner cover and an inner anchoring mechanism,connected by a central stem, similar to FIGS. 27-31. In the embodimentsof FIGS. 32A-32C it is shown that the inner cover and inner anchoringmechanism may have a variation in shape. For example, the inner coverand/or inner anchoring mechanism may have a flat, uncurved shape.Alternatively, the inner cover and/or inner anchoring mechanism may havean angled or curved shape. In this alternative embodiment, the innercover and/or inner anchoring mechanism may have a substantially flatcentral portion with angled or raised edges. FIG. 28, described above,depicts occlusion device 1020 where both the inner cover 1022 and theinner anchoring member 1040 are angled, or curved. FIG. 32A depicts anocclusion device 1420 wherein the inner cover 1422 and the inneranchoring member 1440 are both straight. FIG. 32B depicts an occlusiondevice 1520 wherein the inner cover 1522 is angled and the inneranchoring member 1540 is straight. FIG. 32C depicts an occlusion device1620 wherein the inner cover 1622 is straight and the inner anchoringmember 1640 is angled.

The construction and arrangement of the elements of the aneurysmocclusion device as shown in the various exemplary embodiments isillustrative only. Although only a few embodiments have been describedin detail in this disclosure, those skilled in the art who review thisdisclosure will readily appreciate that many modifications are possible(e.g., variations in sizes, dimensions, structures, shapes andproportions of the various elements, values of parameters, mountingarrangements, use of materials, colors, orientations, etc.) withoutmaterially departing from the novel teachings and advantages of thesubject matter recited herein. For example, elements shown as integrallyformed may be constructed of multiple parts or elements, the position ofelements may be reversed or otherwise varied, and the nature or numberof discrete elements or positions may be altered or varied. It should benoted that the elements and/or assemblies of the system may beconstructed from any of a wide variety of materials that providesufficient strength, durability, or biocompatibility. Othersubstitutions, modifications, changes and omissions may be made in thedesign, operating conditions and arrangement of the preferred and otherexemplary embodiments and medical procedures without departing from thescope of the present invention.

What is claimed is:
 1. An apparatus for treating an aneurysm in a bloodvessel, the apparatus consisting of: a cover disposed on a wire, forcovering a neck of an aneurysm, wherein the cover is configured toexpand from a compressed configuration in a tube to an expandedconfiguration when advanced out of a distal end of the tube to cover theneck of the aneurysm; wherein the cover comprises a sphere of meshmaterial formed into a hemisphere comprising two layers of mesh that isformed by folding a top portion of the sphere into a bottom portion ofthe sphere, such that an inner surface of the cover comprises aconcavity; and wherein the cover is configured to be seated against aninterior surface of the aneurysm adjacent the neck of the aneurysm, andto cover the neck of the aneurysm, without contacting the interiorsurface of the aneurysm at an apex of the aneurysm opposite the neck ofthe aneurysm, and without contacting any of the blood vessel walloutside of the aneurysm.
 2. The apparatus of claim 1, wherein the coverhas a cover diameter and is configured to fit into an aneurysm having aneck diameter that is approximately 1 mm less than the cover diameter.3. The apparatus of claim 1, wherein the cover has a cover diameter andis configured to fit into an aneurysm having a neck diameter that isapproximately 2 mm less than the cover diameter.
 4. The apparatus ofclaim 1, wherein the cover has a cover diameter and is configured to fitinto an aneurysm having a neck diameter that is approximately 4 mm lessthan the cover diameter.
 5. The apparatus of claim 1, wherein the coverhas a cover diameter and is configured to fit into an aneurysm having aneck diameter that is approximately 6 mm less than the cover diameter.6. The apparatus of claim 1, wherein the cover has a thickness of lessthan 100 microns.
 7. The apparatus of claim 1, wherein the cover isbiased toward the expanded configuration.
 8. The apparatus of claim 1,wherein the mesh comprises a plurality of wires or fibers.
 9. Theapparatus of claim 8, wherein the plurality of wires are welded orsoldered together.